PROJECT SUMMARY The recommended (HPV) being Healthy optimizing lack recommendations vaccination US adolescent immunization schedule has expanded to include four vaccines that are routinely for all adolescents: meningococcal conjugate ( MenACWY ) vaccine, human papillomavirus vaccine, tetanus, diphtheria, and acellular pertussis (Tdap) vaccine, and influenza vaccine. Despite a major public health priority, rates of uptake of several adolescent vaccines continue to fall short of People 2020 goals; in particular, uptake of HPV vaccine remains unacceptably low . Multiple barriers to vaccine coverage among adolescents exist, including less frequent health visits by dolescents, of awareness of recommended vaccines by parents and adolescents, and weak or lack of for vaccination by clinicians. Therefore, strategies that can avert missed opportunities for of adolescents in the clinical setting are of critical importance. This proposal a describes a plan of mentored research and training to facilitate the career development of Dr. Hansen, a pediatric infectious diseases specialist, to become an independent clinical investigator in the area of adolescent vaccination. She will accomplishthis through formal coursework and mentored research to 1)gain skills in the research methods necessary to design, perform, and evaluate patient-oriented research aimed at increasing both the acceptance and the uptake of adolescent vaccines, and 2) develop the professional skills and gain the career guidance necessary to successfully transition into an independent investigator. The innovative, interactive prototype mobile app, informed proposed study will refine by qualitative feedback from parents and clinicians, an to support the consistent delivery of recommendations for the vaccines included in the adolescent platform by clinicians to all eligible patients in a way that promotes vaccine acceptance and uptake, (Aim 1) and will then assess Aim user rich t he acceptability of using the refined app during routine clinical care (Aim 2). The proposed method in 2 is not designed to evaluate the effects of the app on the participants, but instead is designed to assess acceptability and to provide data for a future larger cluster randomized study. the resource- infrastructure and supportive environment of Yale to conduct this research, and her She will utilize mentors are experts in clinical research, vaccination, public health, and technology-based health interventions. Through the experience acquired while carrying out the mentored research and training activities described in this proposal, Dr. will translatable anticipated will award Hansen acquire new skills in clinical and health services research and intervention development that will be to future projects . While initial studies will focus on vaccines targeted for use in adolescents, i t is that the knowledge gained through this work will be applicable to a range of different vaccines and have implications for improving the acceptability and uptake of vaccines more broadly. At the end of the period, she will be well-positionedto achieve her goal of developing and testing strategies to improve vaccine coverage and reduce the burden of vaccine-preventable infections as an independent investigator.